Dishwasher latch

ABSTRACT

A latch for a dishwasher which includes, in addition to a fixed strike on the tub, a rotary cam having a perpendicular shaft extending to the outside of the door for manual rotation thereof and a latch pawl pivotable relative to the shaft to lock the shaft against rotation when the door is open but which is pivoted by the strike to release the shaft for rotation when the door is closed. As the cam is rotated with the door closed, one portion of the cam enters the strike to latch the door while another portion of the cam actuates a switch carried on the latch lever.

United States Patent 1191 Mercer 1 Oct. 15, 1974 [54] DISHWASHER LATCHPrimar Examiner-Richard E. Moore 75 In t: R0brtL.M D t ,oh Y 1 ven or eercer ay on Attorney, Agent, or FirmFrederick M. Ritchie [73] Assignee:General Motors Corporation,

Detrolt, Mich. [57] ABSTRACT [22] 1973 A latch for 21 dishwasher whichincludes, in addition is [21] Appl. No.: 386,960 a fixed strike on thetub, a rotary cam having a perpendicular shaft extending to the outsideof the door for manual rotation thereof and a latch pawl pivotable 5292/241 292/DIG' 13 3512 relative to the shaft to lock the shaft againstrotation [58] Fie'ld DIG when the door is open but which is pivoted bythe b strlke to release the shaft for rotation when the door is closed.As the cam is rotated with the door closed, one portion of the camenters the strike to latch the [56] References Cited door while anotherportion of the cam actuates a UNITED STATES PATENTS switch carried onthe latch lever.

3,005,065 10/1961 Jellies 292 0101 69 3,627,960 12/1971 Grabek 292 010.69 2 Chums, 3 Drawmg Flgures 1 DISHWASHER LATCH This invention relatesto a dishwasher and, more particularly, to a combination latch andswitch actuating mechanism therefor which prevents the operation of saiddishwasher until the dishwasher door is closed and latched.

In the dishwasher art, it is common practice to provide an interlockswitch to prevent the operation of the water spray system until thedishwasher door is closed. The prior art also includes a combinationlatch and switch actuating mechanism to perform this job. This inventionis directed to an improved mechanism of this type.

Accordingly, it is an object of this invention to provide an improvedcombination latch and switch actuating mechanism for a dishwasherwherein a latch operating shaft protrudes through the front panel of adishwasher door for locking the door and accuating the switch byrotating the shaft.

Another object of this invention is the provision of a combination latchand switch actuating mechanism which includes a pivotable pawl thatmounts the interlock switch for movement into and out of engagement witha switch actuating cam.

A further object of this invention is the provision for a dishwasher ofa combination latch and switch actuating mechanism which includes aswitch-carrying pivotable pawl having a lock pin thereon movable withrespect to a channel on a latch operating shaft to prevent the rotationof the shaft and, thus, the actuation of said switch when the dishwasherdoor is open.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

IN THE DRAWINGS:

FIG. 1 is a front elevational view of a domestic dishwasher providedwith this invention;

FIG. 2 is a fragmentary sectional view of the combination latch andswitch actuating mechanism of this invention taken along line 2-2 inFIG. 1; and

F IG. 3 is an exploded view of the latch and switch actuating mechanism.

With reference to FIG. 1, the combination latch and switch actuatingmechanism of this invention is shown combined with a dishwasher l0.Dishwasher 10 includes a door 12 hinged about an axis 14 along the loweredge thereof and enclosing a timer 16 for controlling a dishwashingcycle through periods of water spraying within a dishwasher tub 18.

The combination latch and switch actuating mechanism is shown mostclearly in the exploded view of FIG. 3. The mechanism includes anactuator plate 22 attached as at 24 to'an adapter plate 26 on the top ofthe dishwasher tub adjacent the front opening 28 thereof. The actuatorplate has a tongue portion 30 which projects from the front of thedishwasher tub for sensing the presence of the dishwasher door in itsclosed position as will be explained more fully hereinafter.

The actuator plate also includes an opening or latch strike 32 forreceiving a latch cam bolt 34 as will be explained hereinafter.

A latching assembly 36 includes a U-shaped front bracket 38 adjacent afront panel of the dishwasher door and a U-shaped rear bracket 40 inface-to-face relationship with the front bracket and connected theretoto form spaced bearings 42, 44 and a pivot point or axis formed byopenings 46. A switch mounting pawl is pivotally mounted on a pawlmounting pin 52 which extends through openings 46 in the front bracketforming the pivot axis. Spring 53 biases the pawl to pivot normallyclockwise. Interlock switch 54 is mounted by screw 55 to a bottom leg onthe pawl. Pawl 50 also has a central opening 56 from the sides of whichlock pins 58, 60 project radially.

A latch shaft 64 extends through and is rotatably journaled in bearingcollars 42, 44. Locking channels 68, in the shaft receive pins 58, 60respectively as shaft 64 is inserted into the bearing collars of thebrackets.

A latch cam 74 is attached to one end of latch shaft 64 and a latchhandle 78 is attached to the other end of the shaft. Latch cam 74includes a switch actuating cam portion 82 which is adapted to actuatean actuator 84 on interlock switch 54 and the aforementioned latch boltportion 34 which is adapted to lockingly engage with strike 32.

In operation, it is desirable that latch handle 78 not be rotatable whendoor 12 is open. Conversely, when the door is closed, latch handle 78should be rotatable to lock the door and actuate the interlock switch sothat timer 16 may initiate and control a conventional dishwashing cycle.

Thus, when the dishwasher door 12 is open, pawl 50 is biased by spring53in a clockwise direction in a manner tending to pivot switch 54 awayfrom latch cam 74 and to engage lock pins 58, 60 in the locking channels68, 70 of the shaft. This relationship of pin and channel prevents therotation of shaft 64 and, thus, the rotation of cam portion 82 withrespect to the switch actuator 84. Switch 54 remains open and timer 16remains off.

When the dishwasher door 12 is closed, tongue 30 projects into the doorwhere it engages pawl 50 above the pivot formed by pin 52. This causesthe pawl to rotate counterclockwise against the bias of spring 53 andmoves switch actuator 84 sufficiently close to cam portion 82 to enableactuation thereof upon rotation of the latch cam 74. Thiscounterclockwise pivot action of pawl 50 also moves locking pins 58, 60out of locking channel 68, 70 and into an adjacent relationship with anannular groove in the latch shaft. This movement releases the latchshaft for rotation when latch handle 78 is turned. As handle 78 isturned, cam bolt portion 34 moves through the strike opening 32 and, dueto the cam, snugs up and locks the door with respect to the tub. At thesame time, cam portion 82 pushes against switch actuator 84 to conditionthe timer 16 for controlling a dishwashing cycle.

It should be understood that spring 53 may be eliminated within thepurview of this invention by weighting the lower end of pawl 50sufficiently to pivot the pawl clockwise when the door is open.

While the embodiment of the present invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is:

l. A combination latch and switch actuating mecha nism for a dishwasherhaving a tub and a door hingedly mounted with respect to said tub forclosing an access opening in the tub, said mechanism comprising anactuator plate adapted to be affixed to said tub adjacent said accessopening and a latching assembly adapted to be affixed to said door, saidactuator plate having a tongue and a strike, said latching assemblyhaving a latch shaft rotatably mounted with respect to said door, alatch handle affixed on one end of said shaft outside said door forrotating said shaft, a latch cam affixed on the other end of said shaftfor rotation with said shaft, and a pawl mounted for pivoting about anintermediate pivot point thereof with respect to said shaft and saiddoor and having a switch actuator mounted thereon on one side of saidpivot point adjacent said latch cam and normally pivotally spacedsufficiently therefrom when said door is open to prevent actuationthereof, said pawl on the other side of said pivot point adapted toengage the tongue of said actuator plate when said door is closedthereby to pivot said pawl about said pivot point in one direction toplace said switch actuator in a position sufficiently close to saidlatch cam to enable the actuation of said switch actuator by said latchcam when said shaft is rotated, said shaft having an annular groove anda locking channel thereon and said pawl having a lock pin thereonadjacent said shaft, said lock pin pivotally movable between a positionin said groove to permit rotation of said shaft when said door is closedand a position in said locking channel to prevent rotation of said shaftwhen said door is open, said latch cam having a first cam portionlockingly engageable with said strike and a second cam portionactuatingly engageable with said switch actuator when said door isclosed and said shaft is rotated.

2. The combination latch and switch actuating mechanism of claim 1including a spring connected to said pawl on said one side of said pivotpoint tending to pivot said pawl about said pivot point in the oppositedirection when said door is open.

1. A combination latch and switch actuating mechanism for a dishwasherhaving a tub and a door hingedly mounted with respect to said tub forclosing an access opening in the tub, said mechanism comprising anactuator plate adapted to be affixed to said tub adjacent said accessopening and a latching assembly adapted to be affixed to said door, saidactuator plate having a tongue and a strike, said latching assemblyhaving a latch shaft rotatably mounted with respect to said door, alatch handle affixed on one end of said shaft outside said door forrotating said shaft, a latch cam affixed on the other end of said shaftfor rotation with said shaft, and a pawl mounted for pivoting about anintermediate pivot point thereof with respect to said shaft and saiddoor and having a switch actuator mounted thereon on one side of saidpivot point adjacent said latch cam and normally pivotally spacedsufficiently therefrom when said door is open to prevent actuationthereof, said pawl on the other side of said pivot point adapted toengage the tongue of said actuator plate when said door is closedthereby to pivot said pawl about said pivot point in one direction toplace said switch actuator in a position sufficiently close to saidlatch cam to enable the actuation of said switch actuator by said latchcam when said shaft is rotated, said shaft having an annular groove anda locking channel thereon and said pawl having a lock pin thereonadjacent said shaft, said lock pin pivotally movable between a positionin said groove to permit rotation of said shaft when said door is closedand a position in said locking channel to prevent rotation of said shaftwhen said door is open, said latch cam having a first cam portionlockingly engageable with said strike and a second cam portionactuatingly engageable with said switch actuator when said door isclosed and said shaft is rotated.
 2. The combination latch and switchactuating mechanism of claim 1 including a spring connected to said pawlon said one side of said pivot point tending to pivot said pawl aboutsaid pivot point in the opposite direction when said door is open.